MEMS devices are based on using microelectronic wafer fabrication techniques to produce complex shapes in the μm to mm size range with embedded sensors, actuators and circuitry. More than a dimension, MEMS is a way of manufacturing. Presently two types of bulk silicon etching are predominantly used namely, wet and dry etching. Wet etching while offering process simplicity and low cost requires long hours for etching and results in sharp corners and 54.7-degree side wall angles. Dry etching technique namely the Deep reactive Ion etching (DRIE) overcomes the difficulties of wet etching allowing for arbitrary shapes but is an expensive process.
Thus there is a need for an etching technique which offers the simplicity of the wet etching and the process capabilities of dry etching. Such a technique will result in high aspect ratio anisotropic structures without any sidewall angles in a short period of time using standard wet etching methods.